In the case of a part number that has an E within numbers like "0636107208E001", Excel changes the value it stores when it is opened, so even if you change the format of the cells you can never get the original csv data back. The users are double-clicking on an attachment to an email. We are not going to be able to get them to save the file first and them import it into Excel. This only happens once in a while, it is not with every csv file that they get, only if it contains certain data. Since they never have a use for scientific notation (or even know what it is), I was wondering if anyone had found a way to disable Excel ever converting data to scientific notation.